Petroleum fuel consists of hydrocarbons, the most common of which are alkanes. In gasoline the standard is a branched isomer of octane, 2,2,4-trimethylpentane, and the standard for diesel fuel is hexadecane. The average composition of diesel fuel consists of long chain alkanes of 10-16 carbons. Alkanes have other uses as well.  For example, they are used as waxes in candles, in petroleum jelly, and in synthetic polymers. Several processes have been developed to synthesize alkanes both by chemical means and in biological systems.  Many organisms have been reported to produce alkanes. The bacterium that has been reported to produce the most alkanes is Vibrio furnissii M1 as reported by Park, et al. [1] V. furnissii M1 was described as as transforming up to 35% of carbon consumed into hydrocarbon. However, Wackett, et al.[2] were unable to obtain hydrocarbons from this or related microorganisms.  Another rich source of hydrocarbons is the algae Botryococcus braunii; one of the main hydrocarbon components in this green algae is long chain alkanes. [3]

[1] Park, M.O., Tanabe, M., Hirata, K., and Miyamoto, K., 2001, Appl Microbial Biotechnol 56, 448-452.
[2] Wackett, L.P., Frias, J.A., Seffernick, J.L., Sukovich, D.J., and Cameron, S.M., 2007, Appl Microbial Biotechnol 73, 7192-8.
[3] Metzger, P. and Largeau, C., 2005, Appl Microbiol Biotechnol 66 , 486-496.